Surface preparation standard (Swedish

standard)

Surface Preparation type

Description

Sa 1Brush-Off Blast

Cleaning

Removal of loose mill scale, loose rust, and loose paint, to the degree hereafterspecified, by the impact of abrasives propelled through nozzles or by centrifugalwheels. It is not intended that the surface shall be free of all mill scale, rust, and paint.The remaining mill scale, rust, and paint should be tight and the surface should besufficiently abraded to provide good adhesion and bonding of paint. A Brush-Off BlastCleaned Surface Finish is defined as one from which all oil, grease, dirt, rust scale,loose mill scale, loose rust and loose paint or coatings are removed completely buttight mill scale and tightly adhered rust, paint and coatings are permitted to remainprovided that all mill scale and rust have been exposed to the abrasive blast patternsufficiently to expose numerous flecks of the underlying metal fairly uniformlydistributed over the entire surface.

Sa 2Commercial Blast

Cleaning

Removal of mill scale, rust, rust scale, paint or foreign matter by the use of abrasivespropelled through nozzles or by centrifugal wheels, to the degree specified. ACommercial Blast Cleaned Surface Finish is defined as one from which all oil, grease,dirt, rust scale and foreign matter have been completely removed from the surfaceand all rust, mill scale and old paint have been completely removed except for slightshadows, streaks, or discolorations caused by rust stain, mill scale oxides or slight,tight residues of paint or coating that may remain; if the surface is pitted, slightresidues of rust or paint may by found in the bottom of pits; at least two-thirds of eachsquare inch of surface area shall be free of all visible residues and the remaindershall be limited to the light discoloration, slight staining or tight residues mentionedabove.

Sa 2-1/2Near-White Blast

Cleaning

Removal of nearly all mill scale, rust, rust scale, paint, or foreign matter by the use ofabrasives propelled through nozzles or by centrifugal wheels, to the degree hereafterspecified. A Near-White Blast Cleaned Surface Finish is defined as one from which alloil, grease, dirt, mill scale, rust, corrosion products, oxides, paint or other foreignmatter have been completely removed from the surface except for very light shadows,very slight streaks or slight discolorations caused by rust stain, mill scale oxides, orlight, tight residues of paint or coating that may remain. At least 95 percent of eachsquare inch of surface area shall be free of all visible residues, and the remaindershall be limited to the light discoloration mentioned above

Sa 3White Metal Blast

Cleaning

Removal of all mill scale, rust, rust scale, paint or foreign matter by the use ofabrasives propelled through nozzles or by centrifugal wheels. A White Metal BlastCleaned Surface Finish is defined as a surface with a gray-white, uniform metalliccolor, slightly roughened to form a suitable anchor pattern for coatings. The surface,when viewed without magnification, shall be free of all oil, grease, dirt, visible millscale, rust, corrosion products, oxides, paint, or any other foreign matter.

St 2 Hand Tool Cleaning

Removal of all rust scale, mill scale, loose rust and loose paint to the degreespecified by hand wire brushing, hand sanding, hand scraping, hand chipping or otherhand impact tods or by a combination of these methods. The substrate should have afaint metallic sheen and also be free of oil, grease, dust, soil, salts and othercontaminants.

St 3 Power Tool Cleaning

Removal of all rust scale, mill scale, loose paint, and loose rust to the degreespecified by power wire brushes, power impact tools, power grinders, power sandersor by a combination of these methods. The substrate should have a pronouncedmetallic sheen and also be free of oil, grease, dirt, soil, salts and other contaminants.Surface should not be buffed or polished smooth.